Computing devices, such as desktops and mobile computing platforms, may be designed to support one or more peripheral devices such as trackpads, thumbpads, trackballs, isometric joysticks, pen tablets, touch pads, touch screens, mouse devices, etc. The aforementioned peripheral devices may be referred to as spatial input and control (SIC) devices. An SIC device allows the user to provide directional input to the system and applications, access arbitrary locations in the user interface, and issue control commands. Each SIC device and host computer combination defines a range of user functions, actions and modalities an interaction model, or method that affords the user spatial input and control over the system. Each SIC method has distinct advantages for specific activities. Many computing devices feature a single dedicated SIC method, and their applications are therefore designed for a limited range of interactions.
Many of the aforementioned SIC devices have various drawbacks. For example, touch screen devices may require a user to interact via a multi-touch surface in an extended, unsupported posture. The user's hand, wrist, arm, and shoulder may become fatigued after interacting with a touch input device for an extended period of time. As a result, a user's interaction with the device may become increasingly uncomfortable and imprecise. Moreover, direct touch interaction may visually occlude a portion of the graphics presented on a touch screen. These problems may be exacerbated when a dense user interface is utilized.